(ethyl-3-oxobutanoato-O'1,O'3)(2-dimethylaminoethanolato)(1-methoxypropan-2-olato)aluminium(III), dimerised

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Study authors have been advised that, as the ydrolysis reaction is a significant chemical property of the aluminium alkoxides, they should attempt to quantify the rate of reaction for the present compound.
There is a recommended method for determining the rate of hydrolysis of a substance contained in the Official Journal of the European Communicites No. L251 part C10; however, this only applies to water-soluble substances.·It was therefore necessary to design an experiment to measure the hydrolysis of SA2/1/OA

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

(ethyl-3-oxobutanoato-O'1,O'3)(2-dimethylaminoethanolato)(1-methoxypropan-2-olato)aluminium(III), dimerised

EC Number:

402-370-2

EC Name:

(ethyl-3-oxobutanoato-O'1,O'3)(2-dimethylaminoethanolato)(1-methoxypropan-2-olato)aluminium(III), dimerised

Cas Number:

149057-70-5

Molecular formula:

C14H28AlNO6

IUPAC Name:

octaaluminium(3+) octakis((2Z)-4-ethoxy-4-oxobut-2-en-2-olate) octakis(1-methoxypropan-2-olate) octakis(2-(dimethylamino)ethan-1-olate)

impurity 1

Reference substance name:

1-methoxypropan-2-ol

EC Number:

203-539-1

EC Name:

1-methoxypropan-2-ol

Cas Number:

107-98-2

Molecular formula:

C4H10O2

IUPAC Name:

1-methoxypropan-2-ol

Test material form:

liquid

Details on test material:

purified with vacum distillation, analyzed by Gel permeation chromatography as stated in one of the study reports

Study design

Analytical monitoring:

yes

Details on sampling:

research of hydrolysis products : ethylacetaacetate, dimethylaminoethanol, methoxypropanol

Buffers:

xylene

Estimation method (if used):

It was necessary to be able to detect and quantify either SA2/l/OA or its hydrolysis products. We do not at present have a direct means of detecting SA2/l/OA in an easily quantifiable manner, however, since it could be anticipated that the hydrolysis would be rapid we decided to base the method on the detection of the hydrolysis products, namely ethylacetoacetate, dimetbylaminoethanol and methoxypropanol. The method chosen for this was ·gas chromatography because it enabled these hydrolyses products to be separated and quantified. It was also quick and available in-house.

Test Sample
The sample of SA2/l/OA used in these e periments was from batch number 16/2/87, ie. the same material as that used in all the tests conducted under the Notification of New Substances Regulations 1982.

Experiment 1
The gas chromatograph conditions that gave suitable separation are given with a trace of a 1:1:1 ethylacetoacetate, dimethylaminoethanol, metboxypropanol mixture.

Experiment 2
The hydrolysis was carried out by weighing xylene (35g), wate·r ( 15g) and SA2/l/OA (4g) into a clean .and dry 150 ml conical flask (the amou1nt of water used gives a molar ratio of water to aluminium of 69.3:1). The flan;k was then stoppered and clamped to a Griffin flask shaker which was set 1,1t ! speed (approximately 200 oscillations minute-1). After 5 minutes this had fonned an e1nulsion of :itylene, water and SA2/1/0A hydrolysis products. To separate the organic phase, the mixture was filtered through a silicone treated Whatman IPS filter paper (12,5 cm diameter), that had prevfously been washed by passing through 100 ml of xylene. The organic phase wa:, collected as the filtrate and a sample was injected into the gas chromatouraph. The conditions and a sample trace -are shown in Appendix 2. This sho ,s that the peak due to dimethylaminoethanol is now reduced due to strong association with the aqueous phase and that the relatively large xylene peak does not overlap with the areas in which ethylacetoacetate, dimethylaminoethanol and methoxypropanol are to be found.

Experiment 3
A sample of xylene (34.99g) and SA2/1/0A (4,02g) was prepared and this was injected into the gas chromatograph to give the trace shown in Appendix 3 together with the conditions. The peak due to methoxypropanol is present whereas that due to ethylacetoacetate is absent. This infers tha.t there is either some free methoxypropanol present in SA2/l/OA due to incomplete distillation during its preparation or that some decomposition of SA2/l/OA occurs in the chromatography column, It was concluded that the most suitable peak to monitor in the hydrolysis experiment would be that due to ethylac tQacetate. From previous observations of ours and of previous workers\ZJ it is known that ethylacetoacetate bonds more strongly to aluminium than do most alcohols due to its tendeocy to form a chelated structure and it is therefore reasonable to infe that its formation will indicate the hydrolysis of SA2/1/0A.

Results and discussion

Test performance:

HYDROLYSIS EXPERIMENT : Experiment 4
Samples were weighed in the order xylene then SA2/l/OA then water into clean and dry 150 ml conical flasks. The balance used was a Sartorius Modal 1413 MP8-l with a readability of 0.01g.

Each flask was sealed with a B24 ground glass stopper and was attached to the laboratory shaker that was set at approximately 200 oscillations per minute. Flask 1 was removed after 10 minutes shaking, flask 2 after 20 minut11s, flask 3 after 30 minutes and flask 4 after 40 minutes. The contents of ench flask were immediately filtered through a prewashed silicone treated filter paper as described in Experiment 2 to yield an organic phase filtrate which was collected.
The organic phase filtrate of flask 1 was labelled Bxptl2/8/87Rl0 that of flask 2 was labelled Hxptl2/B/87R2, that of flask 3 was labelled HxpU2/8/87R3 and that of flask 4 vas labelled Hxptl2/8/87R4, The filtration operation took approximately 3 minutes to complete in each case.
The organic phase filtrates were injected into the gas chromatograph. The calibration samples described in Experiment 5 were injected during the same session. The results show the height of the peaks observed for the keto and enol forms of ethylacetoacetate presnet in the organic filtrates from experiment 4.

Experiment 5
Four calibration samples were prepared and labelled.

Transformation products:

yes

Identity of transformation products

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

ethylacetoacetate

Molecular formula:

C6H9O3

Molecular weight:

ca. 115

SMILES notation:

CCCC(=O)C(=O)O

Total recovery of test substance (in %)

Remarks on result:

not measured/tested

Remarks:

it could be anticipated that the hydrolysis would be rapid

Dissipation DT50 of parent compound

Remarks on result:

not determinable

Other kinetic parameters:

Under the conditions used in this study hydrolysis of the new substance is complete at 10 minutes.

Results with reference substance:

The average amount of hydrolysis product ethylacetoacetate observed in the hydrolysis as 79% of the theoretical maximum.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions used in this study hydrolysis of the new substance is complete at 10 minutes.

Executive summary:

Under the conditions used in this study hydrolysis of the new substance is complete at 10 minutes.